The present invention relates to colloidally stabilized emulsions, and particularly colloidally stabilized emulsions having reduced or no phenolics.
Phenolics (e.g., phenol-formaldehyde resins), have been used as adhesives, laminates, molding materials, paints and the like. Of particular interest is the use of phenolics as adhesives or binders in non-woven substrates and papers. More specifically, phenolics are used in bonding of refractory shapes; fiber bonding such as in filters; felt bonding; binding of friction products such as brake pads; in papermaking; in insulation; in roofing products; and in the binding of foundry sands such as abrasives. Of particular interest is the use of phenolics in filters. Typically, the filter is provided by impregnating a continuous roll of paper with a phenolic resole in the form of an alcohol solution of a condensate of phenol with formaldehyde. The impregnated and saturated paper is heated to remove the solvent (alcohol) and corrugated to increase surface area. The resin is then cured in an oven and the paper is rolled again. The rolls of the impregnated paper are provided to the filter manufacturer for completion of the process which includes pleating and final curing. Such filters are used in the both air and oil filtering systems in stationary and mobile internal combustion engines.
Phenolics, however, have disadvantages such as high phenol and formaldehyde levels, brittleness when fully cured, slow curing characteristics, instability and poor shelf life. Moreover, phenolics, particularly water-based phenolics, are difficult to use to impregnate fiber substrates. In such impregnation, co-solvents such as alcohols, must be used and then removed.
To this end, it would be desirable to substantially eliminate, or in the alternative, substantially reduce the amount of phenolics used in products and with substrates wherein phenolics have traditionally been used as binders or adhesives.